SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a07b02eb9897dcda4cc30bf4e198c1aa3fca36e63463cfe067e03ca5f599e397' 
  AND token = 'amPAMZR5JmcHZSodr9SHbjOTusy83oBWXpQh1jzIAvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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