SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '274051d764d1413873c014a567c452bb1069b0f4952071b86e06045af41fdf39' 
  AND token = 'XuQb5g+STl1GvX4bz9BktDQ/NDO2YqTXFpbd5UqK7lQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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