SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdbbb249c606743803556c8b095e36e9724f6ca5f2ab526b438ba40820fbaa94' 
  AND token = 'm1KMXRuLNxcnrbZHrRPMVnKhj/sqUeRahb4IUHRMe0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}