SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70b46fd6157fa8fed0dc64b4052fca8f21a3b595d7bdf2b63fa04501df6ebd77' 
  AND token = 'UjsDT4FVoFIA6xUYoJeNANQZaCHuP71QswT+YjB5vok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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