SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c1478be5469298b8db992bcfa9518ed192c7d76f04b67db020720198ce66ab2' 
  AND token = 'ThYoHee5e1GI6q/PnAeXHy71+IC31WWqlQBIWvjZDiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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