SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b5189adf519281fb5c1f37e0bebd3183574c4ef2a65881055671f23ceef9b40' 
  AND token = 'p2Qw7d6uUHlW8HOpEEXRiQSrUaxeQkXxyjPb6YDyGqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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