SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03eabe2578b7371237414046e41acd0f2839c8bd298f33170868ddfb633a90dc' 
  AND token = 'Fu7Hw0EGeT79WCPfruBgSVUZ0o/uncpdpDSLpil2DiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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