SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba47c99f91525fd0e770eb407f464e412d493c472084f2a450ed6682a1bd54d4' 
  AND token = 'W7yKiIPE7jB231p6fnRHlQsYDfB6kFGDTSykXuFd/H4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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