SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d102078d637a13dc764a676a06a9cf20cb61bf09248b3f3a2265f87c8d0e2da' 
  AND token = '59SqPE0wZRlrrP07dBVaiwzw2lpvPw/THNy8jFrtHx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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