SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d9b30a2e1aa57df7d321c23c3cc90917b4fa0ff56a6b6b40de4e128553a5533' 
  AND token = 'YQT2yq9FNUpNKoQSJ2DKhcT8NeVKvy+GOAFH4FpK/Zo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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