SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '629e2525f38b3642294d5ed72378eb71193c2243bcc61f421ec05ebc1711a53f' 
  AND token = 'bqRQXELKSYiyGxY3XUuliHJwiX3NQ/nMLjzVzCa6pWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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