SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87b186592d70b1239bcbe823592c1147b08803600f0bd8d5361242e503d232b1' 
  AND token = 'ppZuL1DqMi5jgtvIyUPx+l7/iTGnDP1JqOjZZzNU8FE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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