SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'eb98148a9bdc99aef916c66042180fa6f24d4d2fda135025b7bf007a579f2ad5' 
  AND token = 'nYMwNp+6jWGjVm+0FGP6MN1g+Z+RdFU9pg6pVQUIrkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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