SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6d3f570320cf7b14efcabe3e56c797466fbeba6261fd410ba7cff1b4d0598382' 
  AND token = 'ttSKlgnmYKpzRSp4BI5MMwZOkqeBrG1Z2PRU3NmKKxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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