SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '943ebb4d1fef84b4e9eab942349d47afb391b1942e3a4ca082ddba8ec57cbc78' 
  AND token = '2J3mGilIzKvaX1kCbvVeJtWgvsecIKDAHKTZX7u+8q8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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