SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '597b938f8253ab83b3c3ef98b53a1612cabafc53e456473f12f0176c69c4919b' 
  AND token = 'zNxtgqEnKdj43NzHRlXJvoI5BOLhDrQC21h1kaIbGCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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