SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '234d09ceb02cab807c956ae197d31fe9cb127e51bc39fc505b58f60529705221' 
  AND token = 'rIBkx98ErX3yyXOxaVoQDh/pinmFvoE0m1BDXDxD6Z4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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