SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d65a20c6906f84e14ee4c4c19beb61493f7dfaaa923fa399ab7c39a37494c6e' 
  AND token = 'mibooxFW55Y0C8napQj4pYseWRedJDpfixGQsjbnYM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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