SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '064f29b6f2d3b92765a5be1fb880c031a901a2c92b144ec513357c47b27ea77d' 
  AND token = 'WyvEstGrsoiMiYBnHSZ9nxc/q2UIJ6jWE09dzpUnQGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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