SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6aea22141a0b3b52eac7b968c1ecbb15962f824118b92c79278c4c1b5b169b75' 
  AND token = 'm6/RpNuhdPkO9gZswFEb4Vxq6oMKpH1AH9nm9rj8fLQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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