SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9dde5c626f198e57fe4415f4c6175a345d1e81a16f7a8ecd2b18146f5c24533' 
  AND token = '8vfhwPPZ/0gIAJiQtV3TO/vLntLUIkvTJqZLzjmL1QM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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