SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cec660d17c471970157f6d6a414bb08deef1262b69cd76a7c2db7894a41b154' 
  AND token = 'H8fDPBSbVmBpOFqUpXbSoDZUMiK2xWVzG2EpOhFWxlc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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