SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '37382875327057f1340eda71382f92ba8c9ec3ed6676fdc59c6727fa680b938e' 
  AND token = 'O1bVsXZmVSDUpmmyvMoNZ/3rSgjMmnBRxtROgyosqLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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