SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f2bbbc3afdc05ea5c4766e4deda613ec70b022d9a312ca75c1fcd2b65564a1a' 
  AND token = '9H7I2yQLu73jJvwP/E3kamuXdeoDNtY/ItLOTmgJIu4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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