SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '29235d800adbadcb8703d1ffa034b6b8051e65dec5d0bfb39bafb1cf2d92e359' 
  AND token = 'elaMlYZVcWZqIhsutiY7yz+DNbzhkpHnVZyV8SLWziM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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