SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59921dc090ebcf33073191f2e9412fe8224f9722a81d6c7f0b305a70de250331' 
  AND token = 'V6xwefSk5pDJX9KjppkPIViMVUzFD0B8Vh7ASTtzjUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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