SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e496ee7fe9224f0db75719e9122ef1ec12a89739e714b2f6970da6f83e281c0a' 
  AND token = '0xtbI+WSXcfgYCLNDGUDPs3eM6fsrCyoBv3zcLXq18k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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