SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9857eb91f48f0f8e0ccb83dbcc7ecfa2c862a6e4c947a64937060a97afffaf60' 
  AND token = 'GOv8Zwf1XBLA8uwXzryMuPKko+OKALorUcbhbkqbp8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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