SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '88339a14b33fe83c34e70a5fff478e716448970bee860f626a1dcf8477913935' 
  AND token = 'xG2xbjzTxE0T+xu3WICDm967sPjpF/onm1zgolagCMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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