SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a0a555887f87fb9ff7a6edf35e939b4f9da1107184b30d083773447707267a9' 
  AND token = 'VY9qDd22M94mUFEjRjYJQXkVBpc2a2E/KYDL8xdky/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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