SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26dddf0628cd3ad8166e52653e5bcc5fc98d9ae29298894b777810ba99d58df2' 
  AND token = 'mvCmRcWTmM3fuCrxEEN0yrx0n2FiUusXnThRbUBmF9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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