SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9b56b1f2a9ff6869d5f74ff05bce554e41d2f0126e841de463cc09c344604ab9' 
  AND token = '9Pyz/4WrDMHoUqsIFgTKHJffmi3EKorxnMV+KL/Fm1I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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