SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b3d5b6b0efb22f295fb3803afb1e3c90dd583efe07d1627205d82365ff4e677' 
  AND token = 'cOKX/Dlqp3siNDFsqjOCTA97lYRW9l7ntIJJzoV+sGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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