SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57433902225bedef406193d4800f7870db6c396b1cc30a815247490751c829f3' 
  AND token = 'Anuw94rEKVErCJIMJMYIsuaV5pUuSBYiNV4zV/oT700=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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