SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dfad67439efa8b69bff5734ff308de538e6322a6962e54141c6c80d297de045' 
  AND token = 'IBxwqIIpFubnR+rh70thMGSm1XRJXdtFtQC8FusExX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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