SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ccc2759192860e79058c9d6a7316e041a39883202bb82d701210dfad1c82f30d' 
  AND token = '7PzwNRSqtzz6bMwdv5+qPlJG5jx8gFTU9C+KLASVDXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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