SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b7c2afb0930c1c8996ad96f3f32c40a507a7799f0f1abbd7a69cacca1e52932' 
  AND token = 'xJpI0VMAhyGaecPqbWeExJiHp/T8PR0h7cTFCkN1r9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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