SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7ca5dc11a0b6f670139dc91c54bd72312f98ba650679ad76d5f2c14617325da0' 
  AND token = 'CoZOAI0xH9a2erxzauEXaUbAV47gDzbD9U+q2/1ilhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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