SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '852060e81a8cbf9e23b39034cab68d416b691a6ae182dc825017a850a6073a58' 
  AND token = 'l0P3uArbmRK1yykw3kv95DodWSV3WAlKa/IZSowuvfc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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