SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df69969f52d6f1418df2db9b7f12191616c9fd341639900867fd9592a6435030' 
  AND token = 'X/uYKG2Ry8kbZ9A7PEuXuY/b4rwKPgST0ViNAHCCQ4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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