SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a624038d427e4a048c0ccdff4ff1168bffb9ea30e0133cac2d7225f529dfa027' 
  AND token = 'ub4bAIqA7Sfj6S1U9DYvYYrypbcDPRdvOYyMlsUc5Zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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