SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b25c547aa49dcf787e3d076bbc94d5bcd58ce8a80785d3abe7e958427a168498' 
  AND token = '1LmqEG+N+BWLOOOZv/fyb5k9VWuAvLlw0rDEMdapI4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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