SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f6430ac3c5b209192877e68b59ad7516000e4fb295162dc66c5bbc4f8596d28' 
  AND token = '+zG1ls483fK3mTRNUDDujt/pK0wgfHB8hMboSd3TVJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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