SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2908f95e33e8180e8f26b528dca3440c43c00e8dea31ef78b1d2b80c92df112' 
  AND token = '28OeNg12PvUUZu70glLzx9t2EVdyQk1gZdiglVp+LSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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