SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'af8cc31d104034f0d8d9f7f7ede8af8704b8161993d66cb70b288ba22bbc31b7' 
  AND token = 'bSMIxp517nbTMhGzCNi4/dESI1GwFs+6bbhXCaMOtKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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