SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '69e79a563a151af58e2d91710f957beed054603c634914d0cd0d44c03bb01735' 
  AND token = 'mVB1UZe/YpM38DplBQtOwQS+SkvRPValcpL6VsRNuvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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