SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84fcbcd0bf194db37a506aa7ac8482cbfe618459b71897a34407d27d6b093b21' 
  AND token = 'AJP4G/Pb8qXZHvApOAHaGR677dYF/FsKIab/1FuAJEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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