SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c6e71721dc278fb7db74e8975632ab6f14a2354b8f00de79c9118d8eba695dbb' 
  AND token = 'zK8R9YGwlyCFimp9qtmmjqSXZA9pCJmBzmkAAyzm6MM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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