SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '49a8943ec72457bfdff3c2139f0f8de836c23e02238b5a64afdf84c8c333ade9' 
  AND token = 'rGon/gbznmvKXGtAoi8YWYviVP1dfXZMNFoGXOUW+QU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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