SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36b6103e7af0b79b6480af52712bc55dfd4122d73772cb1310b02c4e83218dd4' 
  AND token = 'dB1t5kl/N7JSoMoHoRMDmlnHPx0TOw/i7deNKq1CNrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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