SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4881050df2ffc2a56509781c8bcf26d123655271a56323af56aaf8d08b5615c2' 
  AND token = 'i1LzAerHaIwmw+F9UsKcZd1D4DUL20l7LRMfEpm2EPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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