SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a32ef4a8b53262cf69801931728c38fda70d17c1ecf727cd4cff6efbfa664cef' 
  AND token = 'ecNQH0xITI0l0rnRPRyajx2bKB3NBQmAZwoN2hgUB/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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