SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ba69510b4778f436c6ee8d2e1e38d3f088cf90eed7b1aa4ef8a13acdc896d28d' 
  AND token = 'dDrZSIEH9gdQ2sUqHx/VxPtOVgWTCp5lLBwlFVsxC58=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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