SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20f48fb6b8b034154ed29e47df2b33320381ebfcc444243a42875e7bc5f6e3e2' 
  AND token = 'hs+qQSGj/XyEJQ38jBYJZSNmI+7o9zPI6dUnxmQg1Zo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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