SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c7a16b914a6091a1d9c12f00699bcc99682b03c6e7a4aa4ecc5dcc5793c78ee3' 
  AND token = 'MmU7aWrqbahc9xZSyTN9bOyoaaziJDd/DWbRCmlrCck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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