SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58b98cc4a7e86be1d23c673477196691a05cbd8449ea7ff23c67e2dac696cc46' 
  AND token = 'G1JE9ZrWNLrqYznjS+rEVVZ1JGo4veZro8uoHYc+Kqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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