SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28ad7a9dda7890dd8ac19b9a0b8e238aa4ce0db3efa164ba14d1e39117856ecc' 
  AND token = '8O6b2fB4szDrYnxdcNrPrs2lWLu7GST7bvLAvCeFj4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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