SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fe46ae5d06bd7e6575051753a998df29293bb62315890d0afa6e5ca94258b9c' 
  AND token = 'vqfzjsYkZWQ7vfpDHkbFEQJNnJnsqD1+uny2OowWVwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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