SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e618a87199e20bd62bf64c34a73304bb2e2491d96873bffc2e1473bbed670261' 
  AND token = 'KvqWsLOuHaktE8I9d/VG4GQr0eC3NQBxArszGSxselw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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