SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3792edcc4f71d4858486c218c75eb280286dbd6bf4f53dd246e1903cd08ea7c4' 
  AND token = 'SQxl73LSHD2eSyaRT9Rjn/ZgX0xg6E4dvwwAQvZreG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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