SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'f33a2a8981f7eaab5897b659db99643c41d1eb56bc9908fbdbb2c0805a4c9330' 
  AND token = 'bgLTX0IMM2bhOnAupc8jEK+IajW5xo7dzA3TJzShXUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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