SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5ee3a5fb3e6070eeaa762b60a66c9fb59d30aac4fe8bbe8725ad260f7ec0d26' 
  AND token = 'LmEGi7dBQZjMF1GLINXv4kDwwN9QUgTQe1mEkB1brDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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