SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ed707e64cd7726380a69bcf40bf555aa17b6b1b38aec55744dd4b715679e6c2' 
  AND token = 'UvtqYgDAMdmOMv2kN337vLp0mxiNL2Tw6kHjIO9EVCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}