SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea733295ce767a16046abc9e9e0d3889281ad0729d11ab4a05fa120b68fc9229' 
  AND token = 'NCNi21DHR2itSN6bCqetLiSVFuz09yMw4rVimq5ICiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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