SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc1e92fe1b7a8eb33f8942ba6e4b8a2317201a448af61d4955ffaa6b4583c7f0' 
  AND token = 'g1Qq1BZSXj8L/zznw72K6f9lVwVZhkP4Q/WgEpkCoyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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