SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ab53c553cb04418ef9113abc04e5273f081ebf3f80c95a2e071f8f9e850be4f8' 
  AND token = 'mqlCi1fDUkepvLy3x0VxSxuvVNanmfcs8lxEF+0ATEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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