SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9308f9e92e7b79daee80c8fcf4506fbafb2189d9175ef7ad3d31ca1b5182520' 
  AND token = 'DmYnXZ69SKNSt9kYUsj2s8z96dK0YYU+DBa6Y/mBqZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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