SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '383a81d5c47e33d9793a62c64d580158281d318af1d114ceb0173a2bf66ee511' 
  AND token = 'Tox0WoGryYWgxiz1UrrVG6ySIGq6KtoyCGW2Hcnde/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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